“The genetic defects that give rise to gender dysphoria are extremely rare.”
I have never read any study that identified genetic reasons for gender dysphoria, generally; which is not the same as the rare occasions of genetic reasons for malformed genitilia. MOST persons who obtain a gender dyshoria obsession do not have unformed or malformed gentilia or malformed male or female reproductive systems.
I believe those kind of people are called "intersex." (The former word was "hermaphrodite.")
There are several conditions that can cause gender dysphoria, including Klinefelters, Jacob’s, Kallman’s, congenital adrenal hyperplasia, Non-Classic Congenital Adrenal Hyperplasia, hyperthyroidism, and hyperandrogenism. They are typically defects of the endocrine system.
Not everyone affected by these conditions will develop gender dysphoria. In many cases, if the underlying issue is addressed, the gender dysphoria will cease.
To show you how badly the medical system is messed up now, boys with Klinefelters and GD in the past were given testosterone. For the majority, 80% saw relief. Under the current “affirmation” approach, they would be pushed to transition, instead.
Dr. Kenneth Zucker, one of the world’s leading experts in sexual disorders, got run out of his own clinic (only to be vindicated) by a pack of liars because he pushed back on the insanity.